Cheers David, To convert 73.3 Cubic Meters to Megajoules, do I multiple it by 38.61? I seem to read different answers, sometimes asking me to convert to Cubic Feet first. I'm just trying to work out how to get this into 73.3m3 into MJ so I can apply the Heating Value and Pressure Factor and workout how much I've spent on Gas. I believe my previous readings/esitmates may be incorrect but before I speak to my previous provider, I want to ensure I understand the metholodogy correctly. Currently, I' ...